Two-ended clothespin



June 23, 1964 ROB 3,137,906

TWO-ENDED CLOTHESPIN Filed July 2, 1962 United States Patent 3,137,906 TWO-ENDED CLOTHESPIN Roman Rob, Telfes, Stuhai, Tirol, Austria Filed July 2, 1962, Ser. No. 206,661 3 Claims. (Cl. 24-137) This invention relates to a two-ended clothespin, the limbs of which are held together by a coiled tension spring and in which the articulated joints are formed by grooves equally spaced from the coiled spring and projections engaging said grooves. The invention resides in that the projections and grooves are curved in accordance with curves which extend in the parting plane of the limbs.

Two-ended clothespins are known, in which projections and grooves are provided in the parting plane of the limbs, which projections and grooves interengage when the pin is in clamping position and forms articulated joints for the two limbs during the opening movement. In the known embodiments, these projections and grooves are straight so that the required clearance between the tongue and groove results in a transverse twisting of the two limbs because a force tending to twist the two limbs will be applied to them when the two limbs are pressed between the thumb and forefinger of one hand. This twisting of the two limbs, however, is very disturbing when the clothespin is used in practice for fixing clothes or the like.

Such a twisting of the clothespin is precluded according to the invention by the curvilinear interengagement of the projections and grooves so that the clothespin constrains the two limbs or jaws to assume always the correct position.

An embodiment of the invention is shown on the drawing, in which FIG. 1 is a top plan view of one jaw of the clothespin and FIG. 2 is a side view of the assembled pin.

The central portions of two elongated jaws or limbs 1 are held together in a known manner by a helical spring 2 and interengaging projections 3 and grooves 4 on the jaws form two pivots on opposite sides of the spring 2. The axes of these pivots are perpendicular to the axis of the spring 2 and to the direction of elongation of the jaws 2.

To prevent a relative twisting of the two limbs 1 about the axis of the spring 2, the grooves 4 and projections 3 are curved and define curves, which are outwardly concave with respect to the axis of the spring 2. Alternatively, these curves could be outwardly convex provided that their radius of curvature does not equal the distance of the grooves and projections from the axis of the coiled spring 2. The essential feature is that any relative twisting of the two limbs will cause jamming between the projection 3 and groove 4 owing to the interengagement between the projection and groove, and this will prevent the relative twisting of the two limbs so that interengaging projections and grooves prevent a lateral slipping.

I claim:

1. A two-ended clothespin, which comprises two jaws and a coiled tension spring urging said jaws toward each other, said jaws being formed with normally interengaging portions constituting two articulated joints, the axes of said joints defining a plane, said interengaging portions of each joint including a groove and a projection, said grooves and projections being elongated and curved in said plane.

2. A two-ended clothespin as set forth in claim 1, in which said coiled spring is interposed between said joints and said grooves and projections are convexly curved with respect to said coiled spring.

3. A two-ended clothspin as set forth in claim 1, wherein the center of curvature of each of said interengaging portions is spaced from said spring.

References Cited in the file of this patent UNITED STATES PATENTS 36,394 Cone Sept. 9, 1862 2,615,221 Linton et a1 Oct. 28, 1952 2,920,365 Colangelo Jan. 12, 1960 FOREIGN PATENTS 118,458 Australia Apr. 26, 1944 1,177,413 France Dec. 1, 1958 569,630 Italy Nov. 23, 1957 

1. A TWO-ENDED CLOTHESPIN, WHICH COMPRISES TWO JAWS AND A COILED TENSION SPRING URGING SAID JAWS TOWARD EACH OTHER, SAID JAWS BEING FORMED WITH NORMALLY INTERENGAGING PORTIONS CONSTITUTING TWO ARTICULATED JOINTS, THE AXES OF SAID JOINTS DEFINING A PLANE, SAID INTERENGAGING PORTIONS OF EACH JOINT INCLUDING A GROOVE AND A PROJECTION, SAID GROOVES AND PROJECTIONS BEING ELONGATED AND CURVED IN SAID PLANE. 